Growing Concerns: Some pruning decisions don’t make the cut

Staff WriterDecember 30, 2018

If you have trees with low branches that interfere with mowing activities, encroach on structures or interfere with vehicles, they can be pruned to increase clearance.

Ideally, lower branches should be removed on young trees as they develop so that the first branches have adequate clearance as the tree matures. Unfortunately, this process is often overlooked, which can increase pruning needs on larger trees.

The need to prune older trees to “raise” the canopy is a common problem that arborists are asked to address. As with pruning young trees, there are correct and incorrect ways to do this pruning. Unfortunately, this pruning is often done by the individual who mows the lawn. The pruning is usually done incorrectly, which can cause damage to the trees and may pose risk of injury to people.

One common mistake is indiscriminately pruning branches back to a point that is within easy reach. This technique leaves branch stubs just above head height of the person that did the pruning. These stubs can be at an ideal height to poke taller people in the top of the head or even in the eyes.

Proper removal of low branches should be done by pruning them back to lateral branches or the main trunk if they are not too large. Never leave branch stubs protruding where they can become a hazard.

Improper removal of large branches is another common mistake. This creates large wounds and opens the tree to extensive decay. Ideally, it is good to limit cuts to branches 2 inches or smaller in diameter. When larger cuts need to be made it is best to enlist the services of a knowledgeable arborist who understands tree wound response and proper pruning techniques.

An arborist with a good understanding of tree biology has a variety of pruning techniques that can be used to achieve desirable results. This knowledge enables an arborist to know how each tree species will respond to specific pruning techniques. In addition to the current pruning need, we also understand how the tree will respond over time to achieve longer-term results.

Just like young trees require a regular pruning schedule, older trees with low branches or clearance issues will need to be revisited every few years to maintain a desired canopy height.